Electrical system.



E.CONRAU ELECTRICAL SYSTEM, APPLICATION FILED APR.2. I9I3.

1,235,012. @Ifema my 31, 1917.

INVENTOR B @blew ATTORNEY UNITED STATES PATENT OFFICE.

FRAN K CONRAD, 0F SWISSVALE, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSEELEC- TRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRICAL SYSTEM.

Spe'cication of Letters Patent.

Patented July 31, 1917.

To all whom it may concern: l

Be it known that I, FRANK CONRAD, a citizen of the United States, and aresident of Swissvale, in the county of Allegheny and State ofPennsylvania, have invented a new and useul Improvement in ElectricalSystems, of which the following is a specication.

My invention relates to electrical systems, and it has special referenceto such systems as may be employed in the operation of gas engines ofautomobiles and other motor vehicles.

My invention has for its object to provide a simple construction forprotecting the lamps of an automobilefrom an excessive voltage duringthe charging of a storage battery which supplies the lamps.

It is well known that the higher voltage is necessary in charging astorage battery than is furnished by the battery in discharging. Forexample, in a 12 volt battery, about 14 volts is required in charging.It is essential, therefore, in the use of lamps designed-for the batteryvoltage, that some means be employed to protect the lamps whilethebattery is being charged.

I propose to provide a counter electromotivel force in circuit with thebattery and lamps when the battery is being charged. The counterelectromotive force is small, being approximately of a value whichrepresents the difference between the charging and discharging voltagesof the battery.

The single figure of the drawing is a diagrammatic view of circuits andapparatus embodying my invention.

Referring to the drawings, a ,compound wound dynamo-electric machineisprovided with a single armature having a generator armature winding 1and a motor armature winding 2. Thesewindings are connected to separatecommutators and are electrically i independent but may be wound in thesame slots. l

The field magnet windings, which are common to the amature windings,comprise a shunt winding 3, a series winding 4, which is wound to assistthe shunt winding 3, and a differential series winding 5 whichopposesthe windings 3 and 4.

A cutoutor-`automatic switch 6 comprises a core member 7 and two coils 8and 9, respectively, in series and in shunt with the generator armaturewinding 1. The coils 8 and 9 are each connected to a contact member 10.An armature 11, which has a pivotal support at 12, is provided with acontact member 13 to engage the contact member 10 when the armature 11is drawn downwardly.

One terminal of a storage battery 14 is connected to a terminal of thearmature wdinding 2 and its other terminal is grounde directly to thebattery, comprises an interrupter 15 mounted on the shaft 16 of thedynamo electric machine, a distributer 17 An ignition system, that isconnected ture winding 1 and the motor armature winding 2 are controlledby a single pole, double throw switch 'which comprises 'ai movablemember 26 and stationary contact members 27 and 28. It may be assumedthat the dynamo electric machine is operatively connected to the engine(not shown) of an automobile. When the various parts are stationary, andit is desired to start the engine, the switch member 26 is thrown to theleft or starting position to complete a circuit from the ungrounded sideof the battery 14 through the Amotor armature winding 2, the series eldwinding 4, switch member 26, contact member 27 to ground and back to thebattery. The dynamo electric machine then operates as a `'motor to startthe engine. Whergjhmeengine is operating under its own power, theoperator throws the switch member 26 to the right or running position. Acircuit yis then completed from one brush of the 'generatorarmature thruh the series coil and 9 are sufficiently energized to draw the armature11' downwardly against the tension of a spring 29 to connect the contactmembers 10 and 13. The charging circuit,

.which is thus completed, extends from the ungrounded side of thebattery through the motor armature winding 2, series field winding 4:,differential field winding 5, generator armature winding 1, coil 8,contact members 10 and 13 and armature 11, to ground and back to thebattery. The windings 1 and 2 then operate in series to charge thebattery. The winding 1 generates approximately 12 volts andthe winding2, approximately 2 volts. The generator voltage is automaticallyregulated bythe compound windings of the generator field magnet. It-will be noted that, while the above circuit connections are maintained,the lighting system is subjected to the voltage of the generator windingl only. The battery receives the full charging voltage, but the motorwinding 2 is in the circuit which includes the battery and the lamps,with. its electromotive force opposing that of the battery. Y

' When the generator voltage decreases to a value below that of thebattery, the c urrent will be reversed in the charging circuit, and

'the battery will tend to discharge back throu h the generator.

The reversal of current t rough the series coil 8 causes its magneticiield to oppose that of the coil 9 and, as a result, the armature isreleased and is drawn upwardly by the spring 29. `This action separatesthe contact members 10 and 13 to break the charging circuit. Current isnow supplied to the ignition and lighting systems from the battery 14 atits discharge voltage.

It may be lnoted that the windin 2, which generates only two volts, isenab ed to operate as amotor from the 12 volt battery because ofthestrengthening of the field vby cutting out the dierential field windin 5and the drop in potential in the bras es caused by the heavy currentused in starting theengine. The motor winding is in series with thelamps when the battery supplies lighting current, but the lowresistance. of the motor brushes and winding renders the loss -veryslight.- Since the armature wind# ing 2'is designed to generate alowvolta e, and only a small current flows through t e circuit comprisingthe lamps and the motor windings, the torque is insuiicient to rotatethe armature when the battery supplies current to the lighting circuit.

It' willA be understood that, while'I have employed a dynamo-electricmachine as a source of counter electro-motive force to protect thelamps, I may use any other device which will perform the same functions.In the preferred form of my invention, I employ a dynamo-electricmachine with a single armature, but I may, if it is so desired, useseparate machines in the same relations as here illustrated anddescribed.

I claim as my invention:y K

1. The combination with a dynamo-elec tric machine having twoindependent armature windings, a storage battery and a current-consumingtrolling the circuits of said devices whereby a single armaturewindingis connected in circuit with said battery and said device foroperation as a motor, and both of said windings are connected in seriesrelation to each other, one of said windings being interposed betweensaid battery and said device, for operation as a generator. h

2. The combination with a dynamo-electric machine having two independentarmature windings, a storage battery and a current-consuming device, ofmeans for controlling the circuits of said devices whereby a singlearmature winding is connected in circuit with said battery and saiddevice for operation as a motor, and both of said windings are connectedin series relation to each other, one of said windings being arranged inparallel relation to said'device, for operation as a enerator.

3. The combination with a generator winding, a motor winding, f'abattery, a lamp,. and electrical connections between said severaldevices, of means for controlling said connections whereby said motorwinding may receive current from said battery and whereby, when saidbattery receives energy from said windings, said motor winding isconnected in series with said lamp with its electromotive force opposedto that of said'battery.

4. The combination with a dynamo-electric machine having two independentarmature windings, of a storage battery, a current-consuming device, andmeans for connecting said armature windings and said battery in seriesrelation and for connecting one of said windings permanently in circuitwith said current-consuming device, with the electromotive forcegenerated by said winding opposed to that of said battery.

1 5. The combination with a dynamo-electric machine having two separatearmature windings, of a storage battery permanently in circuit with oneof said windin and means for connecting the other of Sai windings incircuit with said battery at a predetermined voltage.

6.v The combination with a dynamo-electric' machine having twoindependent armadevice, of means for conture windings, a storage batteryand a. lcur- In testimony whereof, I have hereunto rent-eonsumin device,of means for consubscribed my name this 29th day of March necting one osaid windings permanently 1913.

. in circuit with said battery and means for FRANK CONRAD. connectingthe other of said windings in Witnesses:

circuit with said battery at a predetermined -R. E. CULmNes, voltage. B.B. Hmm.

